Fix position issues at the “copy” level

Author: julienrf

compiler/src/dotty/tools/dotc/ast/Trees.scala

@@ -1341,10 +1341,17 @@ object Trees {
         case tree: SeqLiteral if (elems eq tree.elems) && (elemtpt eq tree.elemtpt) => tree
         case _ => finalize(tree, untpd.SeqLiteral(elems, elemtpt)(sourceFile(tree)))
       }
-      def Inlined(tree: Tree)(call: tpd.Tree, bindings: List[MemberDef], expansion: Tree)(using Context): Inlined = tree match {
-        case tree: Inlined if (call eq tree.call) && (bindings eq tree.bindings) && (expansion eq tree.expansion) => tree
-        case _ => finalize(tree, untpd.Inlined(call, bindings, expansion)(sourceFile(tree)))
-      }
+      // Positions of trees are automatically pushed down except when we reach an Inlined tree. Therefore, we
+      // make sure the new expansion has a position by copying the one of the original Inlined tree.
+      def Inlined(tree: Inlined)(call: tpd.Tree, bindings: List[MemberDef], expansion: Tree)(using Context): Inlined =
+        if (call eq tree.call) && (bindings eq tree.bindings) && (expansion eq tree.expansion) then tree
+        else
+          // Copy the span from the original Inlined tree if the new expansion doesn't have a span.
+          val expansionWithSpan =
+            if expansion.span.exists then expansion
+            else expansion.withSpan(tree.expansion.span)
+          finalize(tree, untpd.Inlined(call, bindings, expansionWithSpan)(sourceFile(tree)))
+
       def Quote(tree: Tree)(body: Tree, tags: List[Tree])(using Context): Quote = tree match {
         case tree: Quote if (body eq tree.body) && (tags eq tree.tags) => tree
         case _ => finalize(tree, untpd.Quote(body, tags)(sourceFile(tree)))
@@ -1549,7 +1556,7 @@ object Trees {
               cpy.Try(tree)(transform(block), transformSub(cases), transform(finalizer))
             case SeqLiteral(elems, elemtpt) =>
               cpy.SeqLiteral(tree)(transform(elems), transform(elemtpt))
-            case Inlined(call, bindings, expansion) =>
+            case tree @ Inlined(call, bindings, expansion) =>
               cpy.Inlined(tree)(call, transformSub(bindings), transform(expansion)(using inlineContext(call)))
             case TypeTree() =>
               tree

compiler/src/dotty/tools/dotc/ast/tpd.scala

@@ -748,7 +748,7 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
       }
     }
 
-    override def Inlined(tree: Tree)(call: Tree, bindings: List[MemberDef], expansion: Tree)(using Context): Inlined = {
+    override def Inlined(tree: Inlined)(call: Tree, bindings: List[MemberDef], expansion: Tree)(using Context): Inlined = {
       val tree1 = untpdCpy.Inlined(tree)(call, bindings, expansion)
       tree match {
         case tree: Inlined if sameTypes(bindings, tree.bindings) && (expansion.tpe eq tree.expansion.tpe) =>

compiler/src/dotty/tools/dotc/inlines/Inlines.scala

@@ -127,7 +127,7 @@ object Inlines:
       case Block(stats, expr) =>
         bindings ++= stats.map(liftPos)
         liftBindings(expr, liftPos)
-      case Inlined(call, stats, expr) =>
+      case tree @ Inlined(call, stats, expr) =>
         bindings ++= stats.map(liftPos)
         val lifter = liftFromInlined(call)
         cpy.Inlined(tree)(call, Nil, liftBindings(expr, liftFromInlined(call).transform(_)))

compiler/src/dotty/tools/dotc/quoted/PickledQuotes.scala

@@ -81,7 +81,7 @@ object PickledQuotes {
 
   /** Unpickle the tree contained in the TastyExpr */
   def unpickleTerm(pickled: String | List[String], typeHole: TypeHole, termHole: ExprHole)(using Context): Tree = {
-    val unpickled = withMode(Mode.ReadPositions)(unpickle(pickled, isType = false))
+    val unpickled = withMode(Mode.ReadPositions)(unpickle(pickled, isType = false)).asInstanceOf[Inlined]
     val Inlined(call, Nil, expansion) = unpickled: @unchecked
     val inlineCtx = inlineContext(call)
     val expansion1 = spliceTypes(expansion, typeHole)(using inlineCtx)

compiler/src/dotty/tools/dotc/transform/BetaReduce.scala

@@ -82,7 +82,7 @@ object BetaReduce:
           case _ => None
       case Block(stats, expr) if stats.forall(isPureBinding) =>
         recur(expr, argss).map(cpy.Block(fn)(stats, _))
-      case Inlined(call, bindings, expr) if bindings.forall(isPureBinding) =>
+      case fn @ Inlined(call, bindings, expr) if bindings.forall(isPureBinding) =>
         recur(expr, argss).map(cpy.Inlined(fn)(call, bindings, _))
       case Typed(expr, tpt) =>
         recur(expr, argss)

compiler/src/dotty/tools/dotc/transform/Erasure.scala

@@ -637,7 +637,7 @@ object Erasure {
       if (tree.typeOpt.isRef(defn.UnitClass))
         tree.withType(tree.typeOpt)
       else if (tree.const.tag == Constants.ClazzTag)
-        checkNotErasedClass(clsOf(tree.const.typeValue).withSpan(tree.span))
+        checkNotErasedClass(clsOf(tree.const.typeValue))
       else
         super.typedLiteral(tree)
 
@@ -895,11 +895,6 @@ object Erasure {
           tree.typeOpt
         else valueErasure(tree.typeOpt)
 
-    override def typedInlined(tree: untpd.Inlined, pt: Type)(using Context): Tree =
-      super.typedInlined(tree, pt) match {
-        case tree: Inlined => tree //Inlines.dropInlined(tree)
-      }
-
     override def typedValDef(vdef: untpd.ValDef, sym: Symbol)(using Context): Tree =
       if (sym.isEffectivelyErased) erasedDef(sym)
       else

compiler/src/dotty/tools/dotc/transform/PostTyper.scala

@@ -250,7 +250,7 @@ class PostTyper extends MacroTransform with InfoTransformer { thisPhase =>
 
     private object dropInlines extends TreeMap {
       override def transform(tree: Tree)(using Context): Tree = tree match {
-        case Inlined(call, _, expansion) =>
+        case tree @ Inlined(call, _, expansion) =>
           val newExpansion = PruneErasedDefs.trivialErasedTree(tree)
           cpy.Inlined(tree)(call, Nil, newExpansion)
         case _ => super.transform(tree)
@@ -363,7 +363,7 @@ class PostTyper extends MacroTransform with InfoTransformer { thisPhase =>
             case _ =>
               super.transform(tree1)
           }
-        case Inlined(call, bindings, expansion) if !call.isEmpty =>
+        case tree @ Inlined(call, bindings, expansion) if !call.isEmpty =>
           val pos = call.sourcePos
           CrossVersionChecks.checkExperimentalRef(call.symbol, pos)
           withMode(Mode.InlinedCall)(transform(call))

compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala

@@ -1005,7 +1005,7 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
       def apply(call: Option[Tree], bindings: List[Definition], expansion: Term): Inlined =
         withDefaultPos(tpd.Inlined(call.getOrElse(tpd.EmptyTree), bindings.map { case b: tpd.MemberDef => b }, xCheckMacroValidExpr(expansion)))
       def copy(original: Tree)(call: Option[Tree], bindings: List[Definition], expansion: Term): Inlined =
-        tpd.cpy.Inlined(original)(call.getOrElse(tpd.EmptyTree), bindings.asInstanceOf[List[tpd.MemberDef]], xCheckMacroValidExpr(expansion))
+        tpd.cpy.Inlined(original.asInstanceOf[Inlined])(call.getOrElse(tpd.EmptyTree), bindings.asInstanceOf[List[tpd.MemberDef]], xCheckMacroValidExpr(expansion))
       def unapply(x: Inlined): (Option[Tree /* Term | TypeTree */], List[Definition], Term) =
         (optional(x.call), x.bindings, x.body)
     end Inlined